Torque transmission device



Filed July 16, 1940 4 Sheets-Sheet 1 ill R m M W Wk TOR/VEY A. L. DONAHEW TORQUE TRANSMISSION DEVICE Feb.24,1942.

Filed July 16, 1940 4 Sheets-Sheet 2 k RN R.

1N VEN TOR. @Lflanakew 044M ATTORNEY Feb. 24, DONAHEW TORQUE TRANSMISSION DEVICE Filed July 16, 1940 4 Sheets-Sheet 3 INVENTOR. Z/z u LDorra hew v A TTORNEY Patented Feb. 24, 1942 UNITED-STATES PATE N OFFICE M 8 Claims.

amended April 30, .1928; 370 O. G. 75 7) This invention described herein may be manufactured and used by or for the Government for governmental purposes, withoutthe payment to me of any royalty thereon.

This invention relates to a torque transmitting device of the internal shoe type and the primary object thereof is to providea device of this type having inherent dynamic balance and free from any unbalancedforces. i 3

Another object of the invention is to provide a torque transmission clutch of the internal shoe type wherein the centrifugal force-of the shoes is balanced or overcome so that rotation does'not tend to engage the clutch and to provide for the automatic disengagement of the clutch when a predetermined speed isreached. v

A still further object of the invention is to provide a torque transmission device of the internal shoe type, which issimple' in construction, cheap 1 to manufacture and having parts which can be assembled, adjusted and disassembled easily without disturbing adjacent parts thereof.

The structure described herein is particularly adapted for application to the mechanical transmission'device disclosed in the pending application of John W. Marsh and Chauncey F. C. Ma gee, Serial No, 199,274, filed March 31 1938, abandoned August 27, 1940.

Briefly stated, the invention comprises a drum Within which are mounted "apair of identical clutch shoes each of which has embodied therein a cylinder containing'a fluid operated piston. Expanding means comprising levers and toggle mechanisms are provided between each piston and the ends of the shoes. Application of fiuid pressure behind the pistons moves the shoes into contact with the drum and expands the shoes against the drum. All masses and all fo'rcesare diametrically opposite and balanced withinthe clutchmechanism." The weights of the pistons and associated mechanisms are so arranged that the centrifugal forces of the pistons and associated'mechanisms, acting through the expanding means, are equal to or may. be greater thanthe centrifugal force of the shoes (tending to engage the shoes with the drum). When the weight of the pistons and associated mechanisms,

acting through the expanding means, produces a contracting force greater than the expanding force produced by the centrifugal action of the shoes, rotation of the parts keeps the clutch disengaged. When fluid pressure applied to the pistons engages the clutch, the weight of the pistons and associated partscan be arranged to produce a disengaging force overcoming the extion of a transmission panding force of the fluid pressure at any prede termined speed. 1

With the above and other objects andadvantag'es in view, the invention consists of certain features of construction and operation of parts which will hereinafter appear and in which:

Fig. 1 is a front end view partly in section of the improved torque transmission device; Fig. 2 is a fragmentary'side elevation thereof; Fig. 3" is a partial sectional view'of the device in a disengaged position with the greater partof the rear portion thereof removed therefrom; Fig. 4 is a vertical sectional view of the device in a disengaged position'taken on the line 4 4 0fFig.1; 4

Fig. 5 is a longitudinal sectional view of the device in an engaged position takenon the line 5-5 of Fig. 6; Y

' Fig. 6 is a cross-sectional view partly in elevation of thedevice also in the engaged position; j v Fig. 7 is an enlarged sectional view partly in elevation of an expanding and contracting mechanism in a disengaged position including a porof Fig. 3; V

Fig. 8 is an enlarged sectional view partly in elevation of the, expanding and contracting mechanism in an engaged'position with the transmission case removed therefromy Fig. 9 is a fragmentary perspective detail view of a driving member and shaft extension used in carrying out the invention, and g i Fig. 10. is a perspective detailview of an operating lever and toggle links also used in carrying out the invention. v p

In the illustrated embodiment characterizing the invention l indicates a clutch drum formed integral with a driven member 2 and supported in a transmission case 31byroller bearings 4-. A drivingmember 5 illustrated in detail'in Fig. 9,

carrying extension members or driving lugs 6 and 1, is attached to a drive shaft 8 suitably mounted in roller bearings 9 provided within the driven member 2'. An extension It], the purpose of which will hereinafter be described, abuts at its inner end against the inner end of the drive shaft 8 and is fixedly connected therewith in any suitable manner such as by means of projections II which are pressed fitted into recesses 12 formed in the driving member 5 whereby the members 8 and I 0 may be rotated together, Clutch shoes l3 and M are provided which are identical in form and retained in operative p'osi tion within the transmission case} by retaining members I5 and "5 which are securedby bolts ll case talgen on the line -1- to the driving lugs 6 and i. The clutch shoes l3 and I4 are provided with suitable wear surfaces l8 and I8 and cylinders I9 and 23 respectively containing fluid operated pistons 2| and 2| connected by pins 22 and 22, piston links 23 and 23' and pins 24 and 24 to the inner ends of levers 25 and 26 respectively. The outer ends 21 and 21 of the levers 25 and 26 are bifurcated as illustrated in Fig. 10 to engage lugs 23 and 29 provided on the shoes |3 and M respectively by means of pins 33 and 23' and also to engage toggle links 3| and 32 by pins 33 and 33', the said toggle links 3| and 32 also engaging adjusting heads 34 and 35 respectively by means of pins 35 and 35'. The adjusting heads 34 and 35 are provided with threaded portions 37 and 31' carrying adjusting nuts 38 and 38 and with extensions 33 and 39' fitting into recesses 43 and 40' formed in the shoes l3 and M. The cylinders l9 and 20 are provided with ports 4| and '42 respectively illustrated more particularlyin Fig. 5, which are connected by flexible conduits 43 and 44 to an aperture 45 formed in the shaft extension |0. Engaging the inner end of the shaft extension I is a plate46 containing an orifice 41 which registers with'the aperture 45 in the shaft extension as illustrated in Fig. 4. A flexible bellows 48 is attached to the plate 45 and to a cover 49 which is attached to the rear of the transmission case 3 by bolts 50 or the like. The cover 49 of the transmission case 3 is provided with a central orifice which leads into the bellows 48 and to whichis attached a conduit 52 leading to .a' source of operating fluid (not shown). The adjusting heads 34 and 35 are contained within the recesses '49 and 43' in the shoes l3 and |4and the recesses 40 and 43. are formed by walls 53 and 54 having elongated. slots or holes 55 and 56 respectively provided therein through which the pins 33 and 33 extend, as illustrated more parti'cularlyinFigs. '7 and 8, which are enlarged sectional viewsthrough an expanding and contracting mechanism both in a disengaged and engaged position for one of the clutch shoes.

In operation when the drive shaft 8, driving member 5 and the extensions 5 and i thereof are rotated, carrying with them the clutch shoes l3 and M, a centrifugal force is set up in the shoes and their associated mechanisms. This centrifugal force in the shoes i3 and I4 tends to engage the shoes with the drum A centrifugal force also exists in the pistons 2| and 2| contained within the cylinders i3 and 2E! and associated mechanisms.

The centrifugal force applied to the piston 2| and 2| operating through the links 23 and 23' and levers 25 and 23, maintains a centrifugal force on the pins 33 and 33 maintaining the surfaces 5'! and 5'1, on the outerbifurcated ends 21 and 21' ofthe levers 25 and 25 against certain sides of the driving member extensions 6 and 1 respectively, and centripetal force on pins 30 and 35' engaging lugs 28 and 29 on the shoes I3 and [4 thereby maintaining the surfaces 53 and 59 on the shoes in contact with the driving member extensions 5 and Simultaneously the adjusting heads 34 and 35 are drawn toward the driving member extensions 6 and 1 through the toggle links 3! and 32 and pins 36 and 33' engaging the outer surfaces of the elongated slots 55 and 56 in the shoe walls 53 and 54 and drawing the shoes l3 and M together until the surfaces 6|] and 6! on one side thereof and surfaces 62 and 63 on the other side thereof contact with the driving member extensions 5 and 7 respectively. The weight of the pistons 2| and 2| and associated mechanisms are such that their centrfugal force multiplied by the leverage obtained through the toggle mechanism exerts a disengaging force on the shoes l3 and. I4 greater than the engaging force exerted by the centrifugal force on the shoes, by reason of their own weight, and the shoes when rotated without fluid pressure in the operating cylinders l9 and 20 will contract, gripping the driving lever extension 5 and 5 and maintaining a rigid rotating mechanism free from contact with'the clutch drum I.

When fluid pressure is applied through the conduit 52 and orifice 5| in the cover 49 of the transmission case 3 pressure is exerted within the bellows 43 and on the plate 46, whereby the plate 45 is forced into contact with the end 64 of the drive shaft extension l3 maintaining a substantially fluid-tight joint between the plate 45and the end 64 of the shaftextension. The fluid pressure will then be conducted through the orifice 41 to the hole. 45 thence through the flexible conduits 43 and 44 to the cylinders l9 and 23 respectively in shoes l3 and I4 respectively, whereby the pistons 2| and 2| in the cylinders I3 and 29 are forced inwardly toward the shaft extension ID. This inward movement of the pistons 2| and 2| exerts through links 23 and 23' and inward force on the inner ends of the levers 25 and 26 rotating the levers about pins 33 and 30 and 33 and 33'. This rotation of the outer ends 21 and 21 of levers 25 and 25 forces the ends 35 and 65 of the shoes l3 and I4 respectively adjacent to the-lugs 28 and 29, radially outward against the drum I, simultaneously forcing pins 33 and 33' radially inward and forcing pins 36 and 36 substantiallytangentially through toggle links 3| and 32. The tangential force on pins 35 and 36 forces the adjusting heads 34 and 35 tangentially and causes the pins 36 and 35 to slide in the elongated apertures 55 and 55' and the extensions 39 and 39 of the adjusting heads 34 and 35 to recesses 43 and 49' formed in the shoes 13 and I4 respectively, until the adjusting nuts 38 and 38' contact surfaces 51 and 68 on shoes I3 and M respectively. An expanding force is thus exerted between the lugs 28 and 29 on the ends65 and 35 of the shoes and surfaces 61 and 63 expanding the shoes |3 and I4 against the drum I. It will be noted, however, that before any expanding force is exerted between the shoes, the ends 55 and 36 of the shoes adjacent to the lugs 28 and 29 are forced radially against the drum so that the engagement between the shoes L3 and M and the drum is progressive, startingat the ends 35 and 66 adjacent to the lugs 28. and 23. This progressive engagement forces out any liquid which may be between the shoes |3 and l4- and the drum Moreover, since the shoes l3 and M are not attached to either the drum or the driving mechanism but float within the drum, a uniform contact pressure is applied between the surface of the shoes and the drum.

The drive is effected by contact between surfaces 60 and 53 on shoes |3 and I4 respectively, and the driving member extensions 5 and T or between surfaces 6| and 52 on the shoes and the driving'rnember extensions 6 and in the direction of rotation. Equal movement of the pistons 2| and 2| is produced by equalizing lever 69 rotatively mounted on extension I!) and connected to levers 25 and 26 by links in and H tive speed exerts sufficient centrifugal force on the pistons 2I and 2| to overcome the, fluid pressure, the shoes I3 and I4 will be contracted and the clutch disengaged, preventing transmission of torque at speeds greater thanthat pre-, determined by the relative weights of the mem-v bers and the fluid pressure applied, ,Adjustment is effected by rotating the adjusting nuts 38 and 38 on the threaded portions 31 and 31' of the adjusting heads 34 and 35, until the desired angle between levers and 26 and toggle links 3| and 32 is obtained when the shoe liners I8 and I8 on the shoes I3 and I4 respectively, are in contact with the drum I.

It will be apparent since all parts are symmetrical about the center that no unbalanced forces due to the rotation of the parts can exist. It will also be apparent, moreover, that all forces due to applied pressure are balanced by equal opposed forces and that the turning movement on the driving member 2 is balanced so that no extraneous forces are applied to the driving or driven member.

It will be observed that no attachment exists between the shoes I3 and I4, associated mechanism, the driving members drum I or cover49, although the shoes and associated mechanism are substantially rigid with the driving mechanism when rotating either by the action of fluid pressure or centrifugal force on the parts, thus when the device is not rotating and the cover 49 is removed, the entire assembly of shoes and associated mechanisms can be removed without detachment of any member.

With the arrangement shown on the accompanying drawings, the rotation of the shoes I3 and I4 in an anticlockwise direction, as indicated by the arrows when viewed as in Fig. 3, will increase the gri when the shoes contact with the drum I, because of the drag effect. Similarly the rotation of the shoes in a clockwise direction will decrease the grip when the shoes contact vided a novel torque transmitting device, which is well adapted for all the purposes indicated. Even though there has been herein described certain features of construction and operation of parts, it is nevertheless to be understood that various changes may be made therein, if the changes do not depart from the spirit or scope of the claims.

Having described my invention, what I claim as new and wish to secure by Letters Patent is:

1. In a rotative gripping device, a drum, gripping-shoes including ends floatingly positioned within said drum, cylinders provided on said shoes intermediate the ends thereof, said cylinders adapted to have a fluid pressure applied therein, pistons operative within said cylinders, means actuated by said pistons to engage said shoes with said drum when pressure is applied within said cylinders, said means operatively connected to produce a centrifugal force on one end of each of said shoes and a tangential force on one of each of the other ends thereof whereby the entire length of said shoes isexpanded against said drum and means for applying fluid pressure to saidcylinders. V

, 2. In a rotative gripping. device, a drum, grip ping shoes including ends floatingly positioned withinsaiddrum, means adapted to expand said shoes against said drum, said means operatively connected to produce a centrifugal force on one end of each of said shoes anda tangential force on oneof each of the other ends thereof, whereby the entire length of said shoesis expanded against said drum, a driving member positioned coaxially within'said drum and equally spaced arms connected to said driving member, said shoes adapted to transmit tangential forces between said drum and said arms, said tangential forces being divided equally over saidarms; V

3. In a rotative gripping device, a drum, a pinrality of gripping shoes including ends floatingly positioned within said drum, a plurality of means adapted to expand said shoes against said drum, said means operatively connected to produce a centrifugal force on one end of each of said shoes and a tangential force on one of each of the other ends thereof, whereby the entire length of said shoes is expanded against said drum, a driving member positioned axially within said drum and in a plurality of driving contactswith said shoes, each of said shoes, means and driving contacts being identical, equiangularly spaced and having an equal moment arm about a center of said drum.

4. In a rotative gripping device, a drum, a plurality of gripping shoes including ends floatingly positioned within said drum, a plurality of means adapted to expand each of said shoes against said drum, said means operatively connected to produce a centrifugal force on one end of each of said shoes and a tangential force on one of each of the other ends thereof, whereby the entire length of said shoes is expanded against said drum, a driving member positioned axially within said drum, said driving member being in dynamic balance and having a plurality of driving contacts with said shoes, each of said shoes, means and driving contacts being equiangularly spaced and having an equal momentv arm about the center of said drum.

5. In a rotative gripping device, a drum, gripping shoes adjacently and floatingly positioned within said drum, said gripping shoes having ends adjacent to each other, a lever attached to one end of each of said shoes, links attached to each of said levers and to an adjacent end of an adjacent shoe, said levers and links forming toggle mechanisms operatively connected to produce a centrifugal force on one end of each of said shoes and a tangential force on the said adjacent end of the said adjacent shoe whereby the entire length of said shoes is expanded against said drum.

6. In a rotative gripping device, a drum, a driving member positioned axially within said drum, arms connected to said driving member and projecting within said drum, gripping shoes floatingly positioned within said drum, said shoes having attached ends adjacent to each other, levers including inner ends adapted to have a centrifugal force applied thereto and extending from the ends of said shoes toward the center of said gripping device, links connected to said levers and forming toggle mechanisms between the adjacent ends of said shoes, said levers ar ranged to fulcrum on inner surfaces of said arms and to produce a centripetal force on theattached ends of said shoes when' a centrifugal force is applied to inner ends of said levers.

7. In a rotative gripping device, a drum, a driving member positioned axially within said drum, arms including inner surfaces connected to said driving member and projecting within said drum, gripping shoes floatingly positioned within said drum, said shoes having attached ends adjacent to each other, each of said shoes having a projection thereon adapted to engage inner surfaces of said arms, levers including inner ends adapted to have a centrifugal force applied thereto and extending from the ends of said shoes toward a center of said gripping device, links connected to said levers and forming toggle mechanisms between adjacent ends of said shoes, said levers arranged to fulcrum on the inner surfaces of said arms and adapted to produce a centripetal force on the attached ends of said shoes when a centrifugal force is applied to inner ends of said levers to bring said shoe projections into contact with the inner surfaces of said arms.

8. In a torque transmission device, the combination of a driven member, a driving member having axially extending arms positioned coaxially with respect to said driven member, free floating friction shoes positioned for actuated engagement with respect to said driven member, said shoes having their ends arranged to abut against said arms for rotary movement, a series of interconnected levers tying said shoes together, and fluid pressure means interconnecting said shoes and levers to actuate said device.

ARTHUR L. DONAHEW. 

